[AArch64][ISel] Select constructive EXT_ZZI pseudo instruction (#152554) The patch adds patterns to select the EXT_ZZI_CONSTRUCTIVE pseudo instead of the EXT_ZZI destructive instruction for vector_splice. This only works when the two inputs to vector_splice are identical. Given that registers aren't tied anymore, this gives the register allocator more freedom and a lot of MOVs get replaced with MOVPRFX. In some cases however, we could have just chosen the same input and output register, but regalloc preferred not to. This means we end up with some test cases now having more instructions: there is now a MOVPRFX while no MOV was previously needed.
Welcome to the LLVM project!
This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.
The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.
C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.
Other components include: the libc++ C++ standard library, the LLD linker, and more.
Consult the Getting Started with LLVM page for information on building and running LLVM.
For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.
Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.
The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.